The present invention relates to aqueous emulsions of plastic or plastic-elastic materials based on olefin polymers and bitumen.
Bituminous materials (bitumen, tars, pitches, etc.) have only a limited plastic temperature range as defined, for example, by DIN 1995. The difference between the brittle point (DIN 1995, Fraas) and the softening point (DIN 1995, ring and ball) for such materials is small. Methods for considerably widening the plastic temperature range are known. For example, DOS (German Unexamined Laid-Open Application) No. 2,503,782 employs addition of an extensively amorphous homo- or copolymer of propylene and of the distillation residue from cyclododecatriene manufacture. However, such thermoplastic bituminous materials have higher softening points, and can be processed in the molten state only at higher temperatures. Thus, heating of these materials at building sites is required and often can be conducted only with very great difficulty and expense.
Aqueous bituminous emulsions have also been developed. These contain diluents, such as aliphatic and aromatic hydrocarbon, for example xylene. These hydrocarbons are harmful to the environment. Moreover, they are highly flammable and, in part, physiologically harmful. Consequently, the evaporation of the diluent poses significant problems and, as well, entails shrinkage of the mass of material.
Heretofore, it has been impossible to prepare aqueous emulsions from polyolefin-containing, bituminous materials, even by addition of diluents and/or solvents.